Avaliação dos achados no efluente do lavado broncoalveolar nos pacientes com suspeita clinica de pneumonia associada a ventilação mecanica

AUTOR(ES)
DATA DE PUBLICAÇÃO

2000

RESUMO

The aim of this study was to evaluate the frequency of V AP in 1423 patients under mechanical ventilation, based on the results of quantitative culture of the fluid retrieved through BAL. Sensitivity and specificity of the Gram stain, as well as the cellular study, comprising total cellularity and the percentage of alveolar macrophages and neutrophils, were also performed. AlI the patients were under mechanical ventilation for at least 48 hours presenting infiltrate on chest radiographs, associated with purulent tracheal secretion, and were submitted to bronchofibroscopy for BAL. Pneumonia was present (quantitative culture bigger or equal to 104 cfu/ml was used as diagnostic criteria) in 51,2% (63) of the cases, and absent in 48,7010 (60). The Gram stain was positive in 51/63 cases (80,9% of sensitivity) and negative in 56 cases from 60 considered not having pneumonia (93,3% of specificity). The cellular study showed total celIularity more elevated in patients with VAP, with a means of 924.200 cells against 292.044, and 71,4% of the cases with V AP had more than 400.000 cells against only 11,6% in the patients without pneumonia. The presence of neutrophils was more expressive in the patients with VAP (59% against 33,8%). When a cut-off of 50% is used, 90,4% of the patients with pneumonia (57/63) were above that value, while 75% of the patients without pneumonia (45/60) were below. The percentage of alveolar macrophages was higher in the patients without pneumonia. Using a cut-off point of 30%, 86,6% of the patients without pneumonia were above that value, while 71,4% of the patients with V AP were below that value. The most frequent bacterias found in culture was S. aureus, A. baumanii and P. aeruginosa. Only 14.2% (9/63) of the diagnosed pneumonia were polymicrobial. Based on these findings, we can conclude that: a) the frequency of V AP in the study was of 51,2%; b) the most frequent bacterial pathogens found were gram-negative bacilli, besides the S. aureus; c) neutrophil counting above 50% in the fluid retrieved by BAL, and a negative Gram stain, can be used as markers for the presence and the absence of pneumonia, respectively

ASSUNTO(S)

unidade de tratamento intensivo respiração artificial

ACESSO AO ARTIGO

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